The Tissue Procurment and Molecular Techniques (Core B) will play a key role in the Program Project on the Molecular Basis of Male Infertility. The Services to be offered by the Core include: 1). Tissue procurement from the operating room and clinical laboratory 2). Tissue Bank of serum, testis biopsies, sperm, fibroblasts (when available) from fertile and infertile men 3). DMAisolation from blood or tissue for subsequent molecular analysis 4). DMAsequence ABI Prism sequencing machine availability for use by investigators 5). DMA mutation analysis by Trangenomics DHPLC WAVE machine availability for use by investigators 6). Biomek 2000 Laboratory Automation workstation 7). In Situ Hybridization core This Core will provide a central resource for DMA sequencing and mutation analysis using an automated DNA sequencer and the WAVE machine from Trangenomics. Core B will provide in situ hybridization as a service to Project Investigators. All investigators will use this Core. The Tissue Procurement service will collect samples and clinical information on patients with severe male infertility, isolate DNA, keep a computerized database and provide a bank of reagents for Program Project Investigators. It will facilitate the rapid translation of the findings of the basic research investigations into clinical practice and ensure a continued focus of the basic research investigations in areas of clinical relevance. The Tissue Procurement Facility provides accurate patient classification, clinical information, and tissues to the Program Project investigators. Our long-term goal is to use this core to facilitate basic and clinical research investigating the causes, diagnosis, and treatment of male infertility and to translate these findings into clinically useful approaches to male infertility.